The present invention relates to devices and methods for delivering or administering substances, including injection, infusion or inhalation devices and methods for their manufacture and use. More particularly, it relates to devices, features, mechanisms or structures for displaying a dosage setting on an injection, infusion or inhalation device or the like.
In many infusion or injection devices, such as for instance infusion pumps or injection pens for administering insulin, it is possible to set different doses or dosages to be administered. In order to dose correctly when administering a medicine, it is necessary or at least helpful to be able to read the set dosage from the device. To this end, a scale can, for example, be attached to the outer surface of the casing of the device. The dosage to be administered may be set by, for example, a rotational mechanism with the aid of a dosing button. An indicator is simultaneously arranged on the dosing button and assigns the corresponding value on the scale of the casing to a particular dosage rotational position. Providing numerical wheels—for example, for the tens and units of the dosage to be administered—in the interior of the casing of an injection device is also known. The adjacent numerical wheels are rotated further in accordance with setting a dosage. A window is arranged in the wall of the casing, through which the display of the numerical wheels is visible. If the dosage is set with the aid of a threaded rod, it is also possible to attach a scale to said threaded rod. The value of a dosage set, which corresponds to a particular rotational position of the threaded rod, can again be read in a window of the casing of the injection device.
DE 102 29 122, belonging to the owner of the present application, shows, for example, an administering apparatus for an injectable product which comprises a dosage displaying sleeve in the interior of the apparatus, on which the dosage units are printed circumferentially in a spiral. This dosage displaying sleeve is moved relative to the casing by the dosing movement of a dosing and activating means, in order to display the selected product dosage. To this end, a cavity is provided in the part of the casing surrounding the dosage displaying sleeve, in which the dosage unit then appears. A reset cam protrudes from the dosage displaying sleeve, via which the dosage displaying sleeve presses a blocking member out of a blocking engagement with the dosing and activating means by which said means is prevented from moving counter to an activating direction. The dosage displaying sleeve only releases the blocking engagement when it is moved relative to the casing, into a zero-dosage position. This resets the size of the dosage and the display.
A device for dispensing a medicinal fluid in doses, comprising a resettable display means, is known from U.S. Pat. No. 6,364,860, belonging to the owner of the present application, the disclosure of which is incorporated herein by reference. The display means comprises a counting ring which is rotated out of a zero position by a setting movement of an activating means with respect to a casing. A shifting movement of the activating means is mechanically transferred, via a resetting means, into a rotational movement of the counting ring back into its zero position, whereby the counting ring is necessarily rotated continuously back.
U.S. Pat. No. 6,193,698, the disclosure of which is incorporated herein by reference, also belongs to the owner of the present application. It describes a device for administering an injectable product in doses, in which a first display sleeve fixed to the casing and a second display sleeve which can be rotated with the dosing button are provided in order to display the rotational position of the dosing button, i.e. the selected product dosage. One of the display sleeves surrounds the other. Dosage values are disposed on an annular scale of the inner display sleeve and can be read through a window in the outer display sleeve. A shifting block for the dosing button prevents the dosing button from shifting in an uncontrolled way. The dosing button can only be moved back if the display sleeves are in a zero position with respect to each other.
In these known dosage displays, the size of the numbers on the scale is often very small, or numerical values have to be replaced by bars, since sufficient space is not available. In most cases, a round shape of the casing and/or injection device is necessary for forming the mechanism of the dosage display. If the casing has an oval or polygonal shape, the numerical value cannot be arranged near enough to a window or indicator, such that a dosage setting is difficult to read. A dosage display using numerical wheels, or even a digital unit operated via a cam shaft arranged on the dosing rotational mechanism, also takes up a lot of space in the interior of the injection device.